The colorful red rock geology of Sedona looks timeless. But, the complicated topography hides layers of rock that aren't as solid as they appear. And that might - in some places - even pose a threat to humans.
In the 1880's, a local pioneer woman heard a thunderous crash and saw the air filled with a cloud of dust that lingered all day. Soon afterwards, locals discovered why: An immense cylinder of rock had fallen straight down into a hidden cavity, forming a massive sinkhole called Devil's Kitchen.
According to geologist Paul Lindberg, the rock mass that fell may have been 168 feet in diameter and up to 600 feet tall. It collapsed into rubble as it broke, leaving a dimple in the sandstone at the surface.
This simple is the sinkhole - shaped roughly like a fish bowl - narrower at the opening than the bottom. You can visit Devil's Kitchen from the Soldier's Pass Trail, but be careful - stone continues to crumble from its rim.
Other sinkholes exist in the Sedona area too. All of them owe their existence to the deep-buried Redwall Limestone, which slowly dissolves when groundwater moves through t. Though it's covered by hundreds of feet of sandstone, that stone can slowly crack and weaken over time.
Geologists know that many caves pock the hidden Redwall layer. They can't say when, but it's a given that over the long spans of geologic time more collapses will make their way to the surface. leaving surprising new holes in the ground.